Konstantin,

We have the same problem with disposing the ContentPane. I took your example from above and after making a few small modifications. I was able to remove most of the references from the ContentPane but as shown from the Memory profiler below, TabPaneHeader is not allowing the ContentPane to be released. I also included the code below, This is causing a major memory leak in our application. I would really appraciate your help.

Regards

 private void xamDockManager_PaneClosing(object sender, CancellablePaneEventArgs e)
        {
            e.Cancel = true; ContentPane cPane = e.Pane as ContentPane;
           
            UIElement fContent = (UIElement)(cPane).Content;
            //If content is Plan Details call closeform for cleanup
            if (fContent.GetType().Equals(typeof(PlanDetails)))
                ((PlanDetails)fContent).CloseForm();

            //If content is Pivot Container call closeform for cleanup
            if (fContent.GetType().Equals(typeof(PivotContainer)))
                ((PivotContainer)fContent).CloseForm();

            cPane.Content = null;
            xamDockManager.ActivePane = null;

            if (e.Pane.IsFloating == true) e.Pane.IsFloating = false;
            if (cPane != null && cPane.IsPinned == false) { cPane.IsPinned = true; }
            if (this.xamDockManager.Panes.Contains(e.Pane))
            {
                this.xamDockManager.Panes.Remove(e.Pane); return;
            }
            else
                if (e.Pane.OwnerPane is TabGroupPane)
                {
                    (e.Pane.OwnerPane as TabGroupPane).Panes.Remove(e.Pane as ContentPane);

                    (e.Pane.OwnerPane as TabGroupPane).SelectedPane = null;

                }
                else if (e.Pane.OwnerPane is SplitPane)
                    (e.Pane.OwnerPane as SplitPane).Panes.Remove(e.Pane);           
        }